Biomechanical asymmetries persist after ACL reconstruction: results of a 2-year study (original) (raw)
Related papers
Altered Landing Mechanics in ACL-Reconstructed Patients
Medicine & Science in Sports & Exercise, 2013
Purpose: This longitudinal study aimed to examine whether patients with anterior cruciate ligament (ACL) reconstruction show a similar landing strategy during the single-leg hop test (SLHT) postsurgery analog to that previously identified when ACL deficient. It is hypothesized that ACL-reconstructed patients demonstrate greater trunk flexion to reduce knee joint moments at the cost of postural dynamic stability at their involved leg compared to their uninvolved leg. Methods: Ten ACL-reconstructed patients performed a bilateral SLHT 6 and 12 months after surgery. Landing mechanics were determined by means of a soft tissue artifact optimized, rigid, full-body model, and the margin of stability was quantified using an inverted pendulum approach. Knee extensor muscular strength (KS) was assessed during isometric maximal voluntary knee extension contractions. Results: ACL-reconstructed patients showed similar landing strategies as previously reported in their ACL-deficient state. By flexing their trunk, patients repositioned the ground reaction force vector more anteriorly in relation to the joints of the lower extremity (P G 0.05) and, in doing so, were able to transfer joint moments from the knee to the adjacent joints (P G 0.05). This upper body strategy reduced the margin of stability in the ACL-reconstructed leg during landing (P G 0.05). Twelve months after surgery, the ACL-reconstructed leg showed lower KS compared to the uninvolved leg (P G 0.05), and knee joint moment output during landing was significantly correlated to KS. Conclusions: The results highlight the important role of KS on the interaction between trunk angle, joint kinetics, and postural dynamic stability during landing and show that ACL-reconstructed patients use an analogous feedforward strategy (e.g., more flexed trunk) to that used in their ACL-deficient state, aiming to compensate for KS deficits and thereby sacrificing postural dynamic stability and increasing the risk of loss of balance during landing maneuvers.
Applied Sciences
This study investigates whether double-leg and single-leg vertical hops (VH) landing between-limb symmetry in males, an average of two years after anterior cruciate ligament (ACL) reconstruction (ACLR), is associated with postoperative physiotherapy supervision duration. Thirty-eight healthy controls and thirty-eight males after primary unilateral ACLR, with the use of ipsilateral semitendinosus and gracilis tendon autograft, on average two years before, underwent bilateral peak vertical ground reaction force (vGRF) measurements during double-leg and single-leg VH landing, using two force plates. The vGRF was normalized to the body mass (vGRF BM). The vGRF BM limb symmetry index (LSI) was calculated. Tests for dependent and independent samples and linear Pearson’s correlation coefficient (r) calculations were performed. There were significant between-leg differences in the double-leg (p < 0.001) vGRF BM values. The longer the postoperative physiotherapy supervision duration was, ...
JOINT KINEMATICS OF LANDING IN ACL REHABILITATED VOLUNTEERS
The purpose of the present study was to compare the joint kinematics in ACL rehabilitated volunteers during landing from a maximal drop jump. Male (n=6) and female (n=7) volunteers with previous ACL reconstruction and rehabilitation performed a maximal drop jump diagonal side cut task (x20 trials). Knee and hip joint kinematics in all three planes were calculated during the landing component of the task. The range of motion (ROM) of the hip and knee joint, showed differences between the legs. The previously injured leg showed smaller ROM in hip and knee ab-adduction and knee flexion extension. The decreased range of motion in the previously injured leg may be indicative of a less variable landing movement repertoire, which may increase injury risk.
BioMed Research International
The study investigated the vertical jump landing limb symmetry after ACLR between a group of patients receiving a longer supervised physiotherapeutic procedure and following a shorter supervised physiotherapy. Group I (n=20) and Group II (n=15) were males averagely 30 weeks after ACLR. The time since ACLR in both groups (Group I, 27.95 ± 8.26 weeks; Group II, 32.47 ± 7.74 weeks) was insignificant, although the duration of supervised physiotherapy between the two groups (Group I, 27.9 ± 8.26 weeks; Group II, 11.28 ± 8.20 weeks) significantly differenced. Group III (n=20) were controls. Two-legged and one-legged vertical jumps landing vertical ground reaction force (VGRF) were bilaterally measured in all groups using force plates. The intragroup comparison of two-legged jump landing VGRF revealed p=0.01 between the involved and uninvolved limbs in Group II. The intergroup comparison revealed p≤0.001 in the two-legged vertical jump between Groups II and III, and I and II. The one-legge...
Limb asymmetry during recovery from anterior cruciate ligament reconstruction
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2018
There is limited literature that follows a population of Anterior Cruciate Ligament Reconstruction (ACLR) patients through recovery. Our aim was to examine differences in movement and loading patterns across time and between limbs over four visits during 12 months post-ACLR. We hypothesized that kinematic and kinetic data during a stop-jump would have time- and limb-dependent differences through 12 months post-surgery. Twenty-three ACLR athletes performed five vertical stop-jumps at 4, 5, 6, and 12 months post-op with motion capture and force plate data collection. The peak knee flexion (PKF) was different between the 4 and 12, 5 and 6, and the 5 and 12 month visits with earlier months exhibiting higher PKF. The peak vertical ground reaction force (vGRF) was lower at 4 than at 5 and 6 months. The peak posterior ground reaction force (pGRF) was lower at 4 months than all other visits. Frontal knee and sagittal hip range of motion (ROM) were different between 12 months and each previo...
Scandinavian journal of medicine & science in sports, 2014
Asymmetries in sagittal plane knee kinetics have been identified as a risk factor for anterior cruciate ligament (ACL) re-injury. Clinical tools are needed to identify the asymmetries. This study examined the relationships between knee kinetic asymmetries and ground reaction force (GRF) asymmetries during athletic tasks in adolescent patients following ACL reconstruction (ACL-R). Kinematic and GRF data were collected during a stop-jump task and a side-cutting task for 23 patients. Asymmetry indices between the surgical and non-surgical limbs were calculated for GRF and knee kinetic variables. For the stop-jump task, knee kinetics asymmetry indices were correlated with all GRF asymmetry indices (P < 0.05), except for loading rate. Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2) ≥ 0.78, P < 0.01) asymmetry indices. For the side-cutting tasks, knee kinetic asymmetry indices were correlated with the peak propulsion vertica...